Comparison of the Sensory Quality, Image Textures and Color Parameters of Black Chokeberries Dried in a Frozen State by Simultaneous Osmo-Microwave-Vacuum Drying Using Different Osmotic Solutions

Black chokeberry is considered one of the most important superfoods. However, the availability of fresh fruit is seasonal. To ensure consumption throughout the year, chokeberry requires processing. This study was aimed at developing an innovative osmo-microwave-vacuum drying of frozen chokeberries using various osmotic solutions, including sucrose solution, and sucrose substitutes, such as xylitol, fructo-oligosaccharides (FOS), trehalose, maltitol, and erythritol solutions. The sensory attributes, image textures, and color parameters of dried samples were compared to select osmotic solutions other than sucrose ensuring the highest quality of dried chokeberries. Fruit sample dried using FOS solution was characterized by the best and harmonized overall quality with 7.9 points on a linear scale from 0 to 10, followed by chokeberries dried using sucrose solution (7.6) and xylitol solution (7.4). Black chokeberries dried using xylitol and FOS solutions were the most attractive in terms of external appearance with 8.6 and 8.4 points, respectively. Furthermore, chokeberries osmo-microwave-vacuum dried using the FOS solution had the most intense fruity smell (5.1), the most pleasant overall aroma (7.2), the hardest flesh texture (3.8), and were glossy (9.2) and crunchy (8.0) with a long and loud sound while biting. Chokeberries dried using FOS solution were characterized by no statistically significant changes in image textures XHMean, YHMean, and ZHMean after drying and the slightest changes in textures RHMean, GHMean, and BHMean compared to raw material. Considering all color parameters L*, a*, and b*, the determined color difference (∆E) was the smallest for black chokeberries dried using FOS solution (1.03) and xylitol solution (1.74). Therefore, FOS and xylitol solutions were selected as the most appropriate for osmo-microwave-vacuum drying of black chokeberries.